Template:Infobox thorium

Thorium, ₀₀Th
Thorium
Pronunciation	/ˈθɔːriəm/ (THOR-ee-əm)
Appearance	silvery, often with black tarnish
Standard atomic weight Ar°(Th)
	232.0377±0.0004; 232.04±0.01 (abridged);
Thorium in the periodic table
	actinium ← thorium → protactinium
Group	f-block groups (no number)
Period	period 7
Block	f-block
Electron configuration	[Rn] 6d2 7s2
Electrons per shell	2, 8, 18, 32, 18, 10, 2
Physical properties
Phase at STP	solid
Melting point	2115 K (1842 °C, 3348 °F)
Boiling point	5061 K (4788 °C, 8650 °F)
Density (near r.t.)	11.7 g/cm3
Heat of fusion	13.81 kJ/mol
Heat of vaporization	514 kJ/mol
Molar heat capacity	26.230 J/(mol·K)
Atomic properties
Oxidation states	common: +4; −1, +1,? +2, +3
Electronegativity	Pauling scale: 1.3
Atomic radius	empirical: 179 pm
Covalent radius	206±6 pm
	Spectral lines of thorium
Other properties
Natural occurrence	primordial
Crystal structure	face-centered cubic (fcc)
Thermal expansion	11.0 µm/(m⋅K) (at 25 °C)
Thermal conductivity	54.0 W/(m⋅K)
Electrical resistivity	147 n Ω⋅m (at 0 °C)
Magnetic ordering	paramagnetic
Young's modulus	79 GPa
Shear modulus	31 GPa
Bulk modulus	54 GPa
Speed of sound thin rod	2490 m/s (at 20 °C)
Poisson ratio	0.27
Mohs hardness	3.0
Vickers hardness	350 MPa
Brinell hardness	400 MPa
CAS Number	7440-29-1
Isotopes of thorium v; e;
	Category: Thorium; view; talk; edit; \| references

References

^ "Standard Atomic Weights: Thorium". CIAAW. 2013.
^ Prohaska, Thomas; Irrgeher, Johanna; Benefield, Jacqueline; Böhlke, John K.; Chesson, Lesley A.; Coplen, Tyler B.; Ding, Tiping; Dunn, Philip J. H.; Gröning, Manfred; Holden, Norman E.; Meijer, Harro A. J. (2022-05-04). "Standard atomic weights of the elements 2021 (IUPAC Technical Report)". Pure and Applied Chemistry. doi:10.1515/pac-2019-0603. ISSN 1365-3075.
^ Th(-I) and U(-I) have been detected in the gas phase as octacarbonyl anions; see Chaoxian, Chi; Sudip, Pan; Jiaye, Jin; Luyan, Meng; Mingbiao, Luo; Lili, Zhao; Mingfei, Zhou; Gernot, Frenking (2019). "Octacarbonyl Ion Complexes of Actinides [An(CO)₈]^+/− (An=Th, U) and the Role of f Orbitals in Metal–Ligand Bonding". Chemistry (Weinheim an der Bergstrasse, Germany). 25 (50): 11772–11784. 25 (50): 11772–11784. doi:10.1002/chem.201902625. ISSN 0947-6539. PMC 6772027. PMID 31276242.
^ ^a ^b Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. p. 28. ISBN 978-0-08-037941-8.
^ Magnetic susceptibility of the elements and inorganic compounds, in Handbook of Chemistry and Physics 81st edition, CRC press.
^ Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3): 030001. doi:10.1088/1674-1137/abddae.
^ Varga, Z.; Nicholl, A.; Mayer, K. (2014). "Determination of the ²²⁹Th half-life". Physical Review C. 89 (6): 064310. doi:10.1103/PhysRevC.89.064310.

[1] "Standard Atomic Weights: Thorium". CIAAW. 2013.

[CIAAW2021-2] Prohaska, Thomas; Irrgeher, Johanna; Benefield, Jacqueline; Böhlke, John K.; Chesson, Lesley A.; Coplen, Tyler B.; Ding, Tiping; Dunn, Philip J. H.; Gröning, Manfred; Holden, Norman E.; Meijer, Harro A. J. (2022-05-04). "Standard atomic weights of the elements 2021 (IUPAC Technical Report)". Pure and Applied Chemistry. doi:10.1515/pac-2019-0603. ISSN 1365-3075.

[Th(-1),_U(-1)-3] Th(-I) and U(-I) have been detected in the gas phase as octacarbonyl anions; see Chaoxian, Chi; Sudip, Pan; Jiaye, Jin; Luyan, Meng; Mingbiao, Luo; Lili, Zhao; Mingfei, Zhou; Gernot, Frenking (2019). "Octacarbonyl Ion Complexes of Actinides [An(CO)₈]^+/− (An=Th, U) and the Role of f Orbitals in Metal–Ligand Bonding". Chemistry (Weinheim an der Bergstrasse, Germany). 25 (50): 11772–11784. 25 (50): 11772–11784. doi:10.1002/chem.201902625. ISSN 0947-6539. PMC 6772027. PMID 31276242.

[GE28-4] Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. p. 28. ISBN 978-0-08-037941-8.

[magnet-5] Magnetic susceptibility of the elements and inorganic compounds, in Handbook of Chemistry and Physics 81st edition, CRC press.

[NUBASE2020-6] Kondev, F. G.; Wang, M.; Huang, W. J.; Naimi, S.; Audi, G. (2021). "The NUBASE2020 evaluation of nuclear properties" (PDF). Chinese Physics C. 45 (3): 030001. doi:10.1088/1674-1137/abddae.

[Varga14-7] Varga, Z.; Nicholl, A.; Mayer, K. (2014). "Determination of the ²²⁹Th half-life". Physical Review C. 89 (6): 064310. doi:10.1103/PhysRevC.89.064310.

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